He has accepted the Christian definition of "deity" and works to disprove it; his arguments are fairly meaningless to people of faiths who don't accept the Christian definition of "god."

As a devout person of a non-monotheistic religion, I find its inclusion much less inflammatory than, say, an excerpt of the Bible. But mostly, I agree with the people who assume they decided to include it based on recent book sales, and that they're likely to change the "starter pack" for Sony Readers every year or two to match current market preferences, whatever those happen to be.